Annotations: 4NQF

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	HEPN	e4nqfA1	A: alpha bundles	X: Four-helical up-and-down bundle	H: HEPN	T: Nucleotidyltransferase substrate binding subunit/domain	F: HEPN	ECOD (1.6)
B	HEPN	e4nqfB1	A: alpha bundles	X: Four-helical up-and-down bundle	H: HEPN	T: Nucleotidyltransferase substrate binding subunit/domain	F: HEPN	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.20.120.330	Mainly Alpha	Up-down Bundle	Four Helix Bundle (Hemerythrin (Met), subunit A)	Nucleotidyltransferases domain 2	CATH (4.3.0)
B	1.20.120.330	Mainly Alpha	Up-down Bundle	Four Helix Bundle (Hemerythrin (Met), subunit A)	Nucleotidyltransferases domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF05168	HEPN domain (HEPN)	HEPN domain	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	Nucleotidyltransferase	transferase activity nucleotidyltransferase activity catalytic activity transferase activity, transferring phosphorus-containing groups	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR007842	HEPN domain	Domain
A, B	IPR043519	Nucleotidyltransferase superfamily	Homologous Superfamily
A, B	IPR002934	Polymerase, nucleotidyl transferase domain	Domain
A, B	IPR052548	Type VII toxin-antitoxin system antitoxin	Family

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.